1. Field of the Invention
This invention relates to the bonding of thermoplastic parts, and more particularly, to the electromagnetic bonding of a rigid thermoplastic article to a flexible thermoplastic article in forming fluid flow conduit systems.
2. Description of the Prior Art
In the automotive industry, the use of rigid thermoplastic materials in forming air intake conduits parts, such as intake resonators, air cleaner boxes, throttle body bonnets, helm holtz chambers and the like, has substantially replaced the use of metallic materials of construction. Such parts are used with conduits for internal combustion engines and are formed of thermosetting elastomers, such as synthetic rubbers and the like, using mechanical fasteners, such as clamps. While initially effective in sealing the components, after short periods of time, leak paths develop permitting the induction of foreign particles, such as dust, which deleteriously effect engine oil thereby requiring shortened interval for oil changes.
In U.S. Pat. No. 3,620,875, there is disclosed electromagnetic binding between rigid thermoplastic sections using an electromagnetic adhesive composition comprised of particulate electromagnetic energy absorbing material. Such techniques are ineffective in bonding of a thermosetting elastomer, such as rubber, due to its mobility to remelt and bond to a thermoplastic material.
In copending application Ser. No. 08/856,327 filed May 14, 1997, there is disclosed an air intake conduit system comprised of a rigid thermoplastic vessel bonded to a flexible thermoplastic conduit wherein one end of the flexible conduit is clamped onto a metal component of the engine. It has been found that through repeated cycles of heating, that the flexible thermoplastic conduit in contact with the engine exhibits creep properties, i.e. relaxing of physical characteristics requiring periodic resetting of the clamping force.